Why your workout is (probably) wrong

Forget one-size-fits-all workouts. The future of exercise is in
your genes, argues David Epstein, author of The Sports
Gene

iStock

With only 5.5 million residents, Denmark cannot afford to
squander athletes. That's where Jesper Andersen, a physiologist at
the world-renowned Institute of Sports Medicine Copenhagen, comes
in.

Andersen, who was once a national-level 400-metre runner, takes
samples of muscle tissue from elite athletes - from footballers at
F.C. Copenhagen to Olympic runners and rowers - and tailors their
training accordingly. When he found that shot-putter Joachim Olsen
had more fast-twitch muscle fibers - the kind needed for explosive
actions - in his arms than other throwers, he urged Olsen to stop
weight training throughout the year and instead focus on shorter
periods of extremely heavy lifting, followed by periods of total
rest. The result: Olsen's muscle fibers ballooned, he won the
bronze medal at the 2004 Olympics, and was propelled to celebrity
status in Denmark. (He subsequently won the Danish version of
Dancing with the Stars and was elected to parliament.)

When Andersen found greater than 90 per cent slow-twitch muscle
in the shoulder of a kayaker who was struggling to make the Olympic
team in the 500-meter race, he told the man it was a lost cause,
and that he should switch to longer distances. The kayaker did, and
quickly became one of the best long-distance racers in the
world.

Football is the source of Andersen's greatest frustration,
because too often he sees physiologically distinct players trained
identically. "The guys with a lot of [fast-twitch fibers] that can
contract their muscles very fast have much more risk of a hamstring
injury," he says, "but the [football] players are all trained
alike." So he counsels coaches to train players according to their
biology.

Andersen is just one example of a sports scientist applying the
principles of individualised training, an approach that - as I
learned in the reporting of my recent book, The Sports Gene - is being constantly
bolstered by new findings from exercise genetics. In the most
famous exercise genetics study of all time - the HERITAGE Family
Study - DNA was collected from families who were put through five
months of identical training on stationary bicycles. The scientists
conducting the study found genes that helped predict all manner of
changes that the exercisers experienced, from drops in blood
pressure to changes in cholesterol and insulin sensitivity. (They
also documented a small group of people whose genes actually made
them worse in certain health parameters with
exercise.)

In a 2011 breakthrough, the researchers found twenty-one gene
variants - slightly different versions of genes between people -
that predicted changes in the amount of oxygen an exerciser's body
could use. Known as "aerobic capacity," it is a powerful predictor
of endurance. HERITAGE subjects who had at least nineteen of the
"favorable" versions of the genes improved their aerobic capacities
three times as much as subjects who had fewer than ten. And
subsequent studies have found genetic differences that predict
muscle growth with training. The findings render obsolete the idea
of a ubiquitous "10,000 hours rule," in which that amount of
practice necessarily produces expertise. In many cases, it turns
out that our genes actually dictate whose hour of training is most
valuable.

It brings to mind the American College of Sports Medicine motto:
"Exercise is Medicine." Just as medical genetics showed that
different versions of a gene involved in acetaminophen metabolism
ensure that no two people respond quite the same way to a Tylenol,
exercise genetics is showing that no two athletes respond to any
particular training plan quite the same. The era of personalized
training is beginning, but even without genetic testing, every
athlete should keep in mind that the training that works for a
teammate may not be the best for you. If a particular training
stimulus isn't working, don't be afraid to try something else. Like
Jesper Andersen's athletes, and like many of the characters in
The Sports Gene, you may just find the training that best
suits your genome.

David Epstein is an award-winning senior writer for Sports
Illustrated. His new book The Sports Gene: What Makes The Perfect
Athlete (Yellow Jersey Press) is out now, priced £16.99.

David Epstein

David Epstein is an award-winning senior writer for Sports Illustrated. His new book The Sports Gene: What Makes The Perfect Athlete (Yellow Jersey Press) is out now.